I know that it is not completely related to the course but I noticed something strange after I installed the VM to run the appliance. I have inexplicable missing space from /C: without the VM being installed there. In addition, the free space on /C: changes from time to time without me installing anything. For example one day it will be 15GB, some minutes/hours/days later it will be 12,5. Then it will change back to 14 and so on.

Now, I read somewhere that the VMwares sometimes can cause a disk swap since they're using not the computer's RAM but the physical space to run (correct me if it's wrong). Is it true in general and in this particular case? Can someone explain to me how this VM works e.g.what memory it uses etc.?

P.S. Of course, there might be another reason for this but I'm still curious about the VM.

Thanks in advance!

2 Answers 2


Generally speaking, hypervisors (and actually any program) will use system RAM first. If memory gets low, then it will use disk space as an area to 'swap' stuff in and out of RAM. Whether or not this happens to be what is going on in your case I don't know, but if you notice this missing space when running the VM then I would point to that being the likely cause.

  • Ok, I just read that the way the VM works is that it doesn't use the RAM automatically but disk space (no matter if the computer has enough memory). I notice that after the VM it gets considerably low but it's not an isolated case. It happens with other programs too so I guess the VM isn't the only problem. Thanks for your reply
    – GiP
    Commented Feb 1, 2015 at 18:33

You may be confusing disk space with RAM. Check your VM settings. Are you dynamically allocating disk space for storage?

A dynamically allocated file will only grow in size when the guest actually stores data on its virtual hard disk. It will therefore initially be small on the host hard drive and only later grow to the size specified as it is filled with data. A fixed-size file will immediately occupy the file specified, even if only a fraction of the virtual hard disk space is actually in use. While occupying much more space, a fixed-size file incurs less overhead and is therefore slightly faster than a dynamically allocated file.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .